Phentolamine produces its therapeutic actions by competitively blocking alpha-adrenergic receptors (primarily excitatory responses of smooth muscle and exocrine glands), leading to a muscle relaxation and a widening of the blood vessels. This widening of the blood vessels results in a lowering of blood pressure.
Similarly one may ask, what is the use of phentolamine?
Phentolamine is a prescription medication used to reverse numbness after oral and dental procedures, to prevent and control episodes of dangerously high blood pressure, to prevent and treat accidental injection of certain drugs under the skin, and also to diagnose a condition called pheochromocytoma.
how is phentolamine administered? Five milligrams of phentolamine mesylate (phentolamine mesylate) is dissolved in 1 mL of Sterile Water for Injection. The dose for adults is 5 mg; for children, 1 mg. The syringe needle is inserted into the vein, and injection is delayed until pressor response to venipuncture has subsided.
Additionally, what class of drug is phentolamine?
An alpha-adrenergic antagonist, it is used for the treatment of hypertension. It has a role as an alpha-adrenergic antagonist and a vasodilator agent. It is a member of imidazoles, a member of phenols, a tertiary amino compound and a substituted aniline. Phentolamine is an alpha-Adrenergic Blocker.
Why does phentolamine cause tachycardia?
Mechanism. Its primary action is vasodilation due to α1 blockade. Non-selective α-blockers can cause a much more pronounced reflex tachycardia than the selective α1 blockers. Like the selective α1 blockers, phentolamine causes a relaxation of systemic vasculature, leading to hypotension.
19 Related Question Answers Found
What is Regitine used for?
Phentolamine given by injection causes blood vessels to expand, thereby increasing blood flow. When injected into the penis (intracavernosal), it increases blood flow to the penis, which results in an erection. This medicine should not be used as a sexual aid by men who do not have erectile dysfunction.
What is Regitine an antidote for?
Regitine is indicated for the prevention or treatment of dermal necrosis and sloughing following intravenous administration or extravasation of norepinephrine.
Does prazosin lower heart rate?
Prazosin lowers blood pressure without causing a compensatory reflex tachycardia (this is a counteracting fast heart rate – often a physiological response to blood pressure lowering), or a change in the contraction of the heart or the flow of blood through the kidneys.
What is papaverine hydrochloride used for?
Papaverine is a vasodilator that relaxes smooth muscles in your blood vessels to help them dilate (widen). This lowers blood pressure and allows blood to flow more easily through your veins and arteries. Papaverine is used to treat many conditions that cause spasm of smooth muscle.
What is Phenoxybenzamine used for?
This medication is used to treat high blood pressure and heavy sweating due to a certain tumor of the adrenal glands (pheochromocytoma). Phenoxybenzamine belongs to a class of drugs known as alpha blockers. It works by relaxing and widening blood vessels so that blood can flow more easily.
Is there an injection for erectile dysfunction?
Alprostadil is a medicine that men take for ED (erectile dysfunction). You can get alprostadil injected directly into the penis. Or you can use it as suppository, placing it into the opening at the tip of the penis. Injectable alprostadil is sold under the brand names Caverject, Edex, and Prostin VR.
What is papaverine medication?
Papaverine is used to improve blood flow in patients with circulation problems. It works by relaxing the blood vessels so that blood can flow more easily to the heart and through the body. This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
How do you administer phentolamine for extravasation?
Phentolamine (Regitine)2,5 Prepare by diluting 5 mg phentolamine in 10 mL of 0.9% sodium chloride. Inject subcutaneously into the extravasation area within 12 hours of extravasation. Blanching should reverse immediately; additional injections may be required if blanching returns.
What drug is best for erectile dysfunction?
The first things doctors usually prescribe to men with erectile dysfunction are pills like: Avanafil (Stendra) Sildenafil (Viagra) Tadalafil (Cialis) Vardenafil (Levitra, Staxyn)
How does an alpha blocker work?
Alpha blockers lower blood pressure by keeping the hormone norepinephrine from tightening the muscles in the walls of smaller arteries and veins. As a result, the vessels remain open and relaxed. This improves blood flow and lowers blood pressure.
Is yohimbine a drug?
The primary active ingredient in yohimbe is a drug called yohimbine. This is considered a prescription drug in North America. This drug can be safely used short-term when monitored by a health professional. However, it is not appropriate for unsupervised use due to potentially serious side effects that it can cause.
What is an alpha blocker medication?
Alpha blocker: A drug that blocks receptors in arteries and smooth muscle. The alpha blockers include doxazosin (Cardura), prazosin (Minipress), and The alpha blockers include doxazosin (Cardura), prazosin (Minipress), and terazosin (Hytrin).
Does phentolamine have extravasation?
Phentolamine. Phentolamine is an antidote that will counteract the effect of vasoactive agents such as dopamine, epinephrine, norepinephrine and phenylephrine. These medications result in vasoconstriction via stimulation of alpha-receptors. Phentolamine can also be utilized for vasopressin or dopamine extravasation.
What is meant by extravasation?
extravasation (ek-STRA-vuh-SAY-shun) The leakage of blood, lymph, or other fluid, such as an anticancer drug, from a blood vessel or tube into the tissue around it. It is also used to describe the movement of cells out of a blood vessel into tissue during inflammation or metastasis (the spread of cancer).
Does dopamine cause tissue necrosis?
DISCUSSION: Dopamine infusion can cause tissue ischemia or necrosis secondary to vasospasm and extravasation. Although low-dose dopamine has a vasodilatory effect in selected tissues, high concentrations achieved locally as a result of extravasation can still cause severe vasoconstriction and ischemic tissue injury.
What is the treatment for extravasation?
Treatment of a vesicant extravasation includes immediate cessation of infusion, aspiration of as much extravasated drug as possible through the still-intact catheter, and attempts for the aspiration of the extravasated agent in the surrounding tissue. This aspiration may help to limit the extent of tissue damage.
How does alpha blockers cause tachycardia?
In contrast, the blood pressure lowering effects of non-selective alpha blockers, such as phentolamine, are associated with a marked reflex tachycardia due to blunting of inhibitory presynaptic α2 feedback that suppresses the release of norepinephrine when synaptic levels of the neurotransmitter rise.
Do alpha blockers increase heart rate?
OBJECTIVE: Although alpha-blockers are effective in lowering blood pressure, they may increase heart rate, an unwanted effect that could negatively affect outcome. However, the alpha-blocker urapidil might not increase heart rate due to its additional effect on 5-HT1A receptors.
Is adrenaline a norepinephrine?
Norepinephrine is continuously released into circulation at low levels while epinephrine is only released during times of stress. Norepinephrine is also known as noradrenaline. It is both a hormone and the most common neurotransmitter of the sympathetic nervous system. Epinephrine is also known as adrenaline.